PROJECT SUMMARY/ABSTRACT Candidate background: Dr. Glazer received a B.S. from MIT in biology and a Ph.D. from the University of California-Berkeley in evolutionary genetics. As a postdoctoral fellow in Dan Roden's lab at Vanderbilt, he has developed high-throughput methods for studying cardiac ion channels. He has also begun in vitro studies of candidate disease variants discovered through biobank genetics. Research strategy: Thousands of rare Variants of Unknown Significance (VUS) exist in Mendelian disease genes. To improve the accuracy and impact of genomic medicine, the field must develop efficient, scalable methods for identifying variant associations with disease and testing these variants in vitro. This proposal focuses on cell surface transmembrane proteins, which comprise ~20% of the proteome and are associated with many Mendelian diseases. Aim 1 will use genetic discovery in a large biobank to identify new disease-variant associations, using a method to aggregate multi-organ phenotypes called the Phenotype Risk Score (PheRS). PheRS scores will be refined and validated for ~50 candidate transmembrane gene-disease pairs. These scores will be deployed in BioVU, Vanderbilt's biobank (recently expanded to >100,000 genotyped individuals), and other cohorts. Variants will be tested for association with PheRS scores to discover high-priority variants statistically linked with disease. Aim 2 will test the in vitro function of high-priority transmembrane variants using a mixture of gene-specific and general assays. These studies will begin with 4 variants statistically associated with Mendelian diseases by PheRS scores, but still classified as a VUS. This approach will be expanded to test in vitro function of additional variants discovered in Aim 1. Aim 3 will develop and validate Surface-seq, a general method for comprehensively measuring the cell surface trafficking of nearly every variant in a transmembrane protein. This method will first be optimized on a small gene, KCNE1, which is associated with arrhythmias and deafness. It will then be extended to larger transmembrane genes, including BMPR2, a gene linked to pulmonary hypertension. Overall, this work has the potential to identify many new pathogenic/likely pathogenic variants in transmembrane genes. Variants will be reclassified with data from Aims 1-3, and the classifications will be published and deposited into the ClinVar database. Career development and training: This proposal takes advantage of the applicant's expertise in genetics, genomics, and high-throughput assays. It includes many new training opportunities with the Roden and Denny groups and other collaborators, especially involving biobank genetics and new methods for studying transmembrane genes. The additional training will help lead to the candidate's goal of establishing an independent lab studying genomic medicine and transmembrane proteins.